valves or pinging?

Hi, how can I tell the difference between valve misadjusment and
pinging? next time I fill up I am going to try higher octane, 93
instead of 87, if the noise goes away I conclude it is pinging, if the
noise remains I think it must be the valves. is this logic correct or
faulty? thanks

 

valve adjustment does not affect pinging. nor does bad valve adjustment
sound like pinging either. pinging is detonation, much like the noise a
diesel makes. if you're getting it, either your timing is wrong [most
likely], your combustion chambers are coked up, your oxygen sensor is
failing and you're getting too lean a mixture, or there is something
seriously wrong with your gasoline. high octane is more detonation
resistant than low octane so yes, if the noise goes away, it's
detonation with low octane gas.

again, don't get fixated on the valves. they rattle, they don't ping.

 

Thanks, I also noticed that this noise occurs under load when I push
the gas pedal, but if I push even harder it goes away! In other words
only in a certain range of acceleration, too little or too much and the
noise is gone.

Also, it is hard to describe the noise, but to me it sounds like a
vibrator or something like that, i.e. one of those electric thingie
used used for engraving or marking, (don't think of the vibrator some
might use in bed!!!); is that pinging?

 

I have always compared the sound of pinging to beans being shaken in a tin
can. If that's what your pinging sounds like, either your timing is off, or
perhaps you have a cheap quality gas brand (not necessarily low octane) in
the tank. My '93 Accord exhibited the same symptoms with cheap quality gas.

 

You did not mention the type of car you have. I have a 99 Accord and it
came from the factory with a Knock Sensor. If your vehicle came from the
factory with a knock sensor--it might be defective. I believe it works by
retarding the timing when the sensor detects pinging or knocking. After
the sensor determines that the knocking or pinging has gone away--the
timing returns to normal.
If the knock sensor is broken, you will have pinging and knocking problems.

If you decide to trade in the car, make sure the car you buy came from the
factory with a knock sensor.

 

1997 Civic LX 5-speed Manual Transmission, US model. does it come with
a knock (ping) sensor or not? Thanks